Aluminum sulfate and polyaluminum chloride are widely used as coagulants in water treatment plants. A chemical sludge containing aluminium hydroxide, adsorbed organic matter and other water insoluble impurities is obtained after the flocculation-clarification process. In Portugal, an estimated amount of 66 000 ton/yr. (wet wt.) water treatment sludge is being disposed of on land or at municipal solid waste (MSW) landfills. Government restrictions to this practice as well as increasing deposition costs and the potential harmful impacts proceeding from the high aluminium content of the sludge have been leading to significant research efforts in order to evaluate different treatment alternatives, namely involving aluminium recovery and subsequent reuse. Despite membrane-based separation and liquid ion ex-change processes have been studied for that purpose, the traditional acidic and alkaline extraction methods may be still explored to obtain a product susceptible of use as coagulant for industrial waste-water treatment purposes.
Centrifuged chemical sludge from a water treatment plant using polyaluminium chloride as coagulant was characterised in terms of humidity, volatile matter, Al, Fe, Mn, Cd, Cu, Cr, Pb, Ni and Zn. The dry sludge organic content is about 29% and the major elements determined are aluminium (~ 12.6%)...

The taxonomic diversity and antibiotic resistance phenotypes of aeromonads were examined in samples from drinking and waste water treatment plants (surface, ground and disinfected water in a drinking water treatment plant, and raw and treated waste water) and tap water. Bacteria identification and intra-species variation were determined based on the analysis of the 16S rRNA, gyrB and cpn60 gene sequences. Resistance phenotypes were determined using the disc diffusion method.
Aeromonas veronii prevailed in raw surface water, Aeromonas hydrophyla in ozonated water, and Aeromonas media and Aeromonas puntacta in waste water. No aeromonads were detected in ground water, after the chlorination tank or in tap water. Resistance to ceftazidime or meropenem was detected in isolates from the drinking water treatment plant and waste water isolates were intrinsically resistant to nalidixic acid. Most of the times, quinolone resistance was associated with the gyrA mutation in serine 83. The gene qnrS, but not the genes qnrA, B, C, D or qepA, was detected in both surface and waste water isolates. The gene aac(6’)-ib-cr was detected in different waste water strains isolated in the presence of ciprofloxacin. Both quinolone resistance genes were detected only in the species A. media. This is the first study tracking antimicrobial resistance in aeromonads in drinking...

This paper presents a technical feasibility analysis of the incorporation of Rice Husk Ash (RHA), Sludge from Water Treatment Station (SWTS) and Wood Ash (WA) in clay for the mass used in ceramic coating. The methodology involved analyzing the technological properties of various compositions. Samples were prepared for pressing, with compositions from 0 to 50% waste and 50 to 100% clay. The sintering was carried out in a muffle furnace. The properties studied were: solubility and leaching (environmental characterization), water absorption and rupture strength modulus. It was concluded that the best condition was the use of up to 25% of the residuals at temperatures of 1000 ºC, 1100 ºC and 1150 ºC.

OBJECTIVE: This is a case report describing the occurrence of hepatitis A in three workers at a waste water treatment plant during a small community outbreak involving 16 cases. CASE REPORT: The first case was a 26 year old operator who had worked in the plant for two years, the second was a 23 year old employee hired to add new biolite in the secondary treatment area. These two cases never worked together and only met two or three times before the onset of disease in the second case. The third case occurred three months later in a 34 year old ventilation mechanic. All three cases were confirmed by IgM serology and virus was recovered by polymerase chain reaction in the stools of the last two cases. Despite an extensive search for other risk factors for hepatitis A in these workers none was found. CONCLUSION: This report confirms that hepatitis A is an occupational hazard for sewage workers. The numerous potential sources of contamination associated with that occupation support the use of vaccine to provide effective prevention.

We investigated pregnancy outcomes in 101 wives of workers employed in a waste water treatment plant (WWTP), and verified fetal losses by hospital records. Paternal work histories were compiled and each of the 210 pregnancies was assigned a paternal exposure category. The relative risk of fetal loss was increased when paternal exposure to the WWTP occurred around the time of conception.

Disposal of sludge from Water Treatment Plants (WTP) in the environment is very harmful and can cause deterioration of water supplies. Existing methods for treatment of waste produced in ETA are few applied because the costs involved with operation and maintenance. Several alternatives are suggested for the disposal of these wastes, including the application of sludge in agricultural soils can generate several benefits. In this work we evaluated the development of crops with different dosages of WTS (0%, 18.75%, 37.50%, 56.25%, 75%). The sludge used in the study was collected in the ETA Eng. Rodolfo José da Costa, located in Goiânia/GO, which is used in aluminum sulphate (Al2 (SO4) 3) as a primary coagulant. For the study we used five treatments (T1: 25% substrate, 75% land, 0% sludge, T2: 25% substrate, land 56.25%, 18.75% sludge, T3: 25% substrate, 37.50 % land, 37.50% sludge, T4: 25% substrate, land 18.75%, 56.25% sludge, T5: 25% substrate, 0% land, 75% sludget) for four species of native plants occurring in cerrado (Padu-de-óleo; Gonçalo-alves; Canafístula and Ipe-brando). We adopted the completely randomized design (CRD) with four repetitions, totaling 400 plants. The data collections were performed at 30, 60, 90, 120 and 150 days after planting. Parameters such as the collar diameter...

Water treatment plants (WTP) inevitably generates waste (WTPS) that must be disposed properly, however due to its characteristics can be reused in other processes such as
polishing the effluent of stabilization ponds.This work was developed with the intention of
use this waste in the wastewater treatment stabilization ponds, which have good
characteristics of organic matter removal, but low efficiency in nutrient removal. Assays were
performed in Jar Test equipment, wherethefactors: concentrations of the residue, gradient
speed, pH and the time of mixing and sedimentation were varied. It was observed the
influence of each factors in the removal of phosphorus, ammonia nitrogen organic, nitrate,
COD, turbidity and true color. To obtain sufficient volume for analyze the residue formed
after the addition of effluent from maturation pond with water treatment plant sludge (WTPS), sedimentation tests were performed on an acrylic column, using the natural pH of the effluent and a pH modified to 6,0. The residue formed in sedimentation test and the WTPS were characterized as structure and composition. The Jar Test assays showed that there was greater removal of total phosphorus (48,04%), COD (49,39%) and color (50,79%), and that the parameters and the factors had significantly influence in the removal.The waste from sedimentation tests and WTPS consist mainly of sand...

The state of the water supply and
sanitation (WSS) sector in Lebanon is not in line with the
level of economic development reached by the country.
Despite the relatively high coverage rate in the water
sector (78 percent), continuity of supply is extremely low.
The Beirut Mount Lebanon (BML) region, which accounts for 60
percent of total connected households, receives only three
hours of daily water supply during the summer season. The
development of the wastewater sector is still at an
embryonic stage. There are a few waste water treatment
plants in operation, all of which are small. Water storage
capacity is inadequate to meet irrigation water demand, and
is far below the level of other MENA countries. The present
public expenditure aims at examining efficiency and
effectiveness in the allocation of resources in the water
sector. In conducting the research and analysis, the team
observed a contrasted reality in which a multitude of issues
afflicting the sector emerged. Alongside the public
expenditure analysis...

In 2010, 25 water and sewerage projects
with private participation reached financial or contractual
closure in seven low and middle-income countries, involving
investment commitments of US$1.8 billion. In addition, a
second partial divestiture of a water utility in China
raised US$516 million, bringing total investment commitments
for 2010 to US$2.3 billion. That investment remained in the
US$2 billion to US$3 billion range of the last six years.
However, by number of projects, private activity in 2010
declined by 34 percent compared with 2009, reaching the
lowest level in the last 15 years. The lower activity in
China accounted for most of this decline. Overall,
investment was highly concentrated in a few projects. The
three largest projects (one water treatment plant in Mexico,
a wastewater treatment plant in Egypt, and a partial
divestiture of a water utility in China) accounted for 76
percent of investments.

We studied the effects of a waste water treatment plant on organic matter dynamics in Fosso Bagnatore, a Mediterranean stream near Rome (Italy). Concentrations of dissolved organic carbon and seston, along with the standing crops of coarse benthic
organic matter and fine benthic organic matter, were monitored monthly during 2002 in two reaches situated upstream and downstream of a waste water treatment plant effluent. Additionally, we examined two stream functional characteristics: whole
stream metabolism, which was measured from diel changes in oxygen concentrations, and nutrient removal, which was studied by experimental additions of NH4-N, NO3-N and PO4-P. The possible influence of WWTP organic matter alterations on ecosystem
functioning was addressed by measuring epilithon characteristics (standing crop, C:N:P ratios and chlorophyll a content). The WWTP effluent caused an increase (several-fold) of DOC and seston concentrations, and FBOM standing crop, moreover it modified their temporal variation. Downstream of the wastewater treatment plant we detected an higher heterotrophic microbial biomass and a correspondent higher community respiration. The uptake of NH4-N, NO3-N and PO4-P was highly variable probably as consequence of the high variability of the compartments involved (e.g. DOC...

Fonte: Publications Office of the European UnionPublicador: Publications Office of the European Union

Tipo: EUR - Scientific and Technical Research ReportsFormato: Printed

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In the year 2010, effluents from 90 European waste water treatment plants (WWTPs) were collected and analysed in total for 160 organic chemicals and 20 inorganic trace elements. The analyses were complemented by applying also effect-based monitoring approaches aiming at estrogenicity and dioxin-like toxicity analysed by in vitro reporter gene bioassays, and yeast and diatom culture acute toxicity optical bioassays. The analytical work was performed in six European expert laboratories.
This European-wide monitoring study on the occurrence of micropollutants in WWTP effluents represents the largest EU wide monitoring survey on WWTP effluents ever performed. It produced a comprehensive data set on many so far only locally investigated “emerging” compound classes including pharmaceuticals and personal care products (PPCPs), veterinary (antibiotic) drugs, perfluoroalkyl substances (PFASs), organophosphate ester flame retardants, pesticides (and some metabolites) or industrial chemicals such as benzotriazoles (corrosion inhibitors), polycyclic musk fragrances, x-ray contrast agents, Gadolinium compounds, and siloxanes. The obtained results show the presence of 131 target organic compounds in European wastewater effluents, in concentrations ranging from low nanograms to milligrams per liter. These results obtained from 90 different European WWTPs allow the calculation of a European median level for the chemicals investigated.
The most relevant compounds identified in the effluent water samples in terms of frecquency of detection...

By 2030, Africa's urban population
will double, and the difficulties African cities currently
face in providing sustainable water services will be
exacerbated. 'The future of water in African cities:
why waste water?' argues that the traditional approach
of one source, one system, and one discharge cannot close
the water gap. A more integrated, sustainable, and flexible
approach, which takes into account new concepts such as
water fit to a purpose, is needed in African cities. The
book provides examples of cities in Africa and beyond that
have already implemented Integrated Urban Water Management
(IUWM) approaches both in terms of technical and
institutional solutions. Case studies explore the ways in
which IUWM can help meet future water demand in African
cities. Recent work carried out by Bahri (2012) on IUWM for
the Global Water Partnership has also emphasized the
necessity to examine the challenges posed by urban sprawl
for urban planners and to recognize the need for coordinate,
response, and sustainable resource management across
sectors...